Billionaire entrepreneur Elon Musk unveiled a zippy video Thursday night showing the progress his company has made on a tunnel beneath the city of Hawthorne, part of his grand vision for a subterranean transportation network that whisks commuters across Los Angeles County.

Yet even as he celebrates that milestone, Musk faces new challenges on another underground project: a 2.7-mile tunnel planned along Sepulveda Boulevard on L.A.’s Westside.

Two neighborhood groups have filed a lawsuit over the city of Los Angeles’ proposal to fast-track the project by exempting it from environmental review. In Culver City, where the Sepulveda tunnel could end, officials are contemplating their own court challenge. And debate continues over the effect Musk’s transportation initiative could have on surface traffic, economic equity and the environment.

“There’s pressure in Silicon Valley for companies to move fast and break things,” said Meghan Sahli-Wells, Culver City’s vice mayor. “But those companies don’t have to pick up the pieces. … We’re not going to let them come in here without a plan.”

Two Westside organizations, the Brentwood Residents Coalition and the Sunset Coalition, sued L.A. this month, saying the city violated state law when it sought to waive environmental review for the tunnel.

Musk’s Boring Co. has posted images online showing a spider web of possible tunnel routes across L.A., with proposed stations at the Getty Center, Dodger Stadium, Union Station and Los Angeles International Airport. Opponents say that map is evidence that the proposed Westside tunnel, which would start near Pico and Sepulveda boulevards, is part of a much larger planned underground transportation network.

The lawsuit said state law bars agencies from giving “piecemeal” approval to one component of a larger construction project. The state’s environmental law “cannot be evaded by chopping large projects into smaller pieces that taken individually appear to have no significant environmental impacts,” the suit said.

Last month, the Los Angeles City Council's public works committee unanimously agreed to exempt the tunnel from environmental analysis, which can add months or years to project timelines. The move still needs a full council vote.

In March, a city commission approved the route that the Boring Co. would use for hauling 80,000 cubic yards of dirt from the Westside tunnel. The panel also determined the project is exempt from state environmental law, according to the lawsuit. The two Westside groups are challenging both actions.

A spokesman for Mayor Eric Garcetti had no comment on the lawsuit, and a representative of the Boring Co. did not respond to questions Friday from The Times. The firm would conduct an environmental review if it moved forward with plans for passenger service in L.A., a Boring Co. official said last month.

The Boring Co. has said its technology could move drivers, as well as pods carrying passengers and bicyclists, through tunnels at speeds of up to 130 mph. A video simulation released by the company last year shows a driver steering onto a car-sized platform on the street, parallel to the curb. The platform, called a skate, sinks downward like an elevator, then carries the car through the tunnel.

The Boring Co.

An artist's rendering of a pod loading passengers on a skate.

An artist's rendering of a pod loading passengers on a skate. (The Boring Co.)

The Boring Co. is set to participate in a town hall-style meeting Thursday at Bel-Air’s Leo Baeck Temple. One online flier for the event read, “Please join us to learn more about the Boring Company’s vision to alleviate soul-destroying traffic through Loop, a zero-emissions, high-speed, underground public transportation system!”

The video posted on Instagram shows a sped-up trip through the Hawthorne tunnel on a narrow railway track. Musk said in the caption that the public will be able to take free rides in the tunnel in a few months, “pending final regulatory approvals.”

Faced with Musk’s bold vision and aggressive timelines, cities in Los Angeles County will be forced to balance the painstaking process of public planning with efforts to innovate and embrace new technology, experts said.

Officials from the Metropolitan Transportation Authority, which has jurisdiction over county transportation projects, met with Boring Co. employees last month. In a statement, Metro said the Boring Co. will coordinate with the agency to avoid conflicts between Musk’s proposed tunnel and a heavy rail line planned through the Sepulveda Pass.

An environmental review could help address residents’ fears that tunneling in an earthquake-prone area could damage their homes or pose a threat to public safety, said Jim Moore, a USC professor who is a longtime critic of Metro’s subway projects. Approving a project without that information also could expose the city to lawsuits, he said.

As rich as Musk may be, Moore said, “L.A.’s pockets are deeper.”

Santa Monica City Manager Rick Cole criticized L.A.’s push for the environmental exemption, arguing that two council members are “trying to ingratiate themselves with a billionaire to promote a misguided approach to transportation.”

Cole, a former deputy mayor to Garcetti, argued that the project will undermine L.A.’s work in discouraging sprawl, considered a major contributor to greenhouse gases. He also warned that the tunneling project could create a new class divide among commuters.

“We’ll have people stuck in traffic on the surface, and this miracle fast lane underground for the people who can afford it,” he said. “It’ll be toll lanes on steroids.”

City Councilman Paul Koretz, who is pushing for the exemption, disputed the notion that he is currying favor with Musk. “Billionaires are all over my district,” said Koretz, who represents Bel-Air, where Musk has a home. “I don’t particularly care. I treat them like anyone else.”

Koretz said he is acting because he is excited by the technology being pursued by the Boring Co. and hopes the project can be built more quickly and at a lower cost than other forms of transportation — and at no government expense.

“I would like to see something like this take us from LAX to Westwood to the Valley at a minimum by the Olympics” in 2028 — when L.A. will host the Summer Games and Westwood will play a major role, he said.

In recent weeks, Koretz has helped set up tours of the Hawthorne test site for neighborhood leaders in his district.

Barbara Broide, president of the Westwood South of Santa Monica Boulevard Homeowners Assn., got to see the entrance to the tunnel but did not go inside. She said the tour did not change her opinion that the project needs more environmental review than Garcetti and the council are contemplating.

“It should have more rigorous discussion,” Broide said. “It looks like a transportation project, and I want to know why it’s not being reviewed like a transportation project.”